Control system



W. A. RAY

CONTROL SYSTEM Jung 5, 1945.

Original Filed May 14, 1940 3 4 7 w 1. w 8, 5 2 2 6 5 4 2 55 5 9 9 III!4 3w 3 m 3 r 2 1 5 4 1 1 2 iU m m a w 2 F/ 5 2 ML b mm m 5 M 1. 5 9 0 5/4 5 7 M F 2 5 5 m 0 v II\\\\\\\\\\\\\\\\\\\\\\\\\$W/IZIIIIIIIIIIIIIIIIA\ I 3nventor; WILLIAM A.PA v, %4 4 (Ittorneg.

Patented June 5, 1945 UNITED STATES PATENT orrics William A. Ray, LosAngeles, Calif. v

Original application May 14, 1940, Serial No 335,085. Divided and thisapplication April 19,

1943, Serial No. 483,544

5 Claims. (Cl. 236-84) This invention relates'to control systems forfluid-fuel consuming heating apparatus; the present application being adivision of my copending application, Serial No. 335,085, filed May 14,1940, now Patent 2,317,639, dated April 27, 1943.

An object of this invention is to provide-in a burner control systemcomprising electricallycontrolled valve means adapted to supply fuel toa main burner in such amounts that either a low-fire or a high-firecondition thereat can be established-a pair of thermoelectric generatingdevices for energizing the valve means; one of these devices beingarranged to be heated by the main burner, and the other by asupplemental burner.

Another object is to provide a system, of the character described in thepreceding object, wherein one of the thermoelectric generating devicesis heated by a continuously-burning pilot burner for the main burner andis capable of providing energy to the valve means in-an amount such thatthereby a low-fire condition can be established; the otherthermoelectric generating device, heated by the main burner, beingcapable of providing an amount (or, additional amount) of energysufficient for the establishment of the high-fire condition.

Other objects and advantages of the invention will be found in thedescription, the drawing, and the claims; and, for full understanding ofthe invention, reference may be had to the following detaileddescription and accompanying drawing, wherein:

Figures 1, 2 and 3 are diagrammatic views of a valve, of a type adaptedfor use in connection with the thermoelectric generating means of myinvention, and including an electrical control system; the parts beingshown in the several views in the positions which they assume inoperation; and

Figure 4 is a diagrammatic view of a thermoelectric system, embodyingthis invention, adapted for the control of the valve shown in Figs. 1-3.1

Referring first to Figs. 1, 2 and 3 of the drawing, the numeral l5indicates a valve casing having an'inlet l6 and an outlet separated by apartition Hi. This partition has a main port opening l9 therethrough,provided at its upper and lower ends, respectively, with valve seats 20and 2|. A flexible diaphragm 22, covering an opening in the top wall ofthe valve casing, carries a closure member 23 provided with an upper 24and a lower 25 valve member cooperable, re-

. communicating with the port spectively, with the seats 20 and 2|.Defining, with the valve casing, a pressure chamber 26 above thediaphragm 22, is a housing 21. Secured to the top of this housing, anddefining therewith another chamber 28, is another housing 29.

Mounted in the chamber 26 is a first electromagnetically operated pilotvalve 30 comprising a pivoted armature 3|, the upper end portion ofwhich serves as a closure member for jets 32'and 33, which are connectedrespectively by pipes 34 and .35 with the inlet l6 and the chamber 28.The armature is normally held in engagement with jet 33 by the force ofa spring-3B and is movable, when core 31 is energized by current flow incoil 38, into engagement with the other jet 32. Mounted in the chamber28 is a second electromagnetically operated pilot valve 39, similar tothe pilot valve 30, and comprising a pivoted armature 40, the upper endportion of which is cooperable with jets 4| and 42 which are connectedrespectively by pipes 43 and 44 with a.

formed in the partition l8. and I9, and with the atmosphere. Thearmature is biased by a spring 46 into engagement with the jet 4| and ismovable, when core 41 is energized by current flow in coil 48, intoengagement with the jet 42.

A thermostat suitable for automatic control of the valve comprises abimetallic member 49 which carries a contact element 50 cooperable witha. fixed contact 5| connected to one terminal of the coil 48. Secured tothe bimetallic member i a resilient arm 52 which carries another contactelement 53 cooperable with another fixed contact 54 connected to oneterminal of the coil 38. The other terminals of the coils are connectedtogether and to the bimetallic member through a source of current 55.The contacts are so arranged that, in the anticlockwise movement of thebimetallic member from the position shown in Fig. 1, engagement of theelements 53 and 54 is efiected before that of elements 50 and 5|; theresilience of the arm 52 permitting the subsequent additional engagementof the latter pair. Similarly, when the bimetallic member subsequentlymoves in the opposite direction, elements 50 and 5| are disengagedbefore elements 53 and 54.

Assuming that the valve shown in Figs. 1-3

passageway 45 is connected to supply gas to the burner of a fur-.

is completely obstructed by the valve member 24 which is maintained bygravity in engagement with the seat surrounding the inlet end of portl9; fluid pressure above and below the diaphragm 22 being equalized bythe open jet 32 of pipe 34, and the chamber 26 being closed from theatmosphere by the engagement of the armature with jet 33.

On cooling, the bimetallic member 39 moves in an anti-clockwisedirection and thus, if the temperature in the space falls, the" contacts53 and 54 engage and current flows in coil 38, energizing the core 31 toattract the lower end of the armature which assumes the position shownin Fig. 2. Jet 32 now being closed and jet 33 open, the fluid which wascompressed in chamber 26 escapes to the atmosphere throughpipe 35,chamber 28 and pipe 44, as indicated by the broken arrows in Fig. 2. Thepressure of the fluid in the inlet Hi can now force the diaphragmupward, the closure member assuming the positionshown in Fig. 2 with thevalve member 25 in engagement with the lower or outlet end of the port I9. In this position of the closure member, fluid can flow to the burnerthrough a restricted passageway 56 formed in the partition l8 andinterconnecting the port l9 and the outlet H. A low-fire condition thus.now exists at the burner, it being assumed that the fuel was ignited by.a continuously burning pilot burner'or other igniting means.

It will be noted thatythe closure member, in passing from thepositionshown in- Fig. l to that shown in Fig. 2, passed through anintermediate position (shown in Fig. 3) wherein both ends of the port H!were open. A momentary high flow of fuel to the burner .was thuspermitted which ensured proper and complete ignition.-

If, in spite of the low-fire condi-tion of the furnace burner, the spacecontinues to cool, the

bimetallic member will, move farther, efiectingj engagement of contacts.EO'and in addition to.

that of contacts 53 and 54. The core ll, thus being energized,magnetically moves the armature 40 to the position shown in Fig. 3wherein jet 4| is open andjet 42 closed. Fluid can now flow, asindicated by the broken arrows in Fig. 3, from the relatively highpressure zone existing in port H! (the lower end of which is closed)through passageway 45, pipe 43, open jet H, chamber 28 (which. is nowclosed from the atmosphere) pipe 35, and open jet 33 into the pressurechamber,26 above. the diaphragm which was previously at atmosphericpressure. The resultant increase inpressure above the diaphragm,opposing that below it, permits the closure member to fall to theintermediate position shown in Fig. 3 wherein it is balanced by thepressures andits weight. The factor controlling the balanceis thepressure drop across the upper end of port, 19 which increases as themember 2t approaches the seat 20. The resistance of the jet openings,which in practice are preferably quite small. has no effect on the finalbalance of the closure member, as the pressure is then static. I

In the balanced position of-theclosure member, full flow. through thevalve is permitted to efiect a high-fire? condition at the burner. If-the temperature in the space now rises, the thermo-,

static member will move in a clockwise direction to first open contacts56 and 5|, with the result that armature 40 will be released, closingjet ll and opening jet 12. Thecompressed fluid can then escape from thechamber 26 to the atmosphere and .the closure member will reassume itslow-fire position as shown in Fig. 2. Under normal heating conditions,the valve will be operated intermittently between its lowand highfirepositions. Should the temperature in the space rise above apredetermined degree, both pairs of thermostat contacts will open,deenergizing pilot valve and thus subjecting the chamber above thediaphragm to the full pressure of thefiuid to completely shut-oil fuelsupply tothe burner.

Referring now to Fig. 4wherein the thermo- 1 electric system of thisinvention is shown arranged for the control of the valve disclosed inFigs. 1-3, when the same is employed to control fuel supply to agas-consuming heating apparatus-the numeral 68 indicates a bimetallicmember, responsive to the result of the heating,

and carrying a first contact element 6|, cooperable with a fixed contact62. Secured to the bimetallic member is a resilient arm 63 which carriesa second contact element 64, cooperable with another fixed contact 65.The fixed contact 65 is connected by a wire 66 to one terminal of anelectroniagnet coil 5?, the other terminal of which is connected byawire 68 to one terminal of a thermoelectric generating device orthermopile 69 which is so arranged as to be heated by the name of apilot burner Ill for a main burner H. Similarly, the fixed contact 62 isconnected by a wire l2 to one terminal of another electromagnet coil 73,the other terminal of which is connected by a wire H to one terminal ofanother thermopile '55 which is arranged to be heated by the flame ofthe main burner H. The other terminals of the thermopiles are connectcdtogether by a wire 76, and to the bimetallic member by wire ll. Adaptedto be energized respectively by current flow in the cells 51 and 73 areU-shaped cores l8 and ":19 with which jetcontrolling armatures and 8!are respectively coopera'ble.

The jets with which armature 80 cooperates correspond to the jets 32 and33 of the valve shown in Figs. 1-3 and serve to control the initialoperation of the main closure member from closed to low fire positionwhen contacts 64 and G5 engage with fall of temperature at thebimetallic member. Current for the operation of this armature isprovided by the 'thermopile 6:? which is heated by the flame of thecontinuously burning pilot burner Ill. The system is therefore always incondition for initial operation. When the main burner is in low-firecondition, the other thermopile is heated and current is then availablefor the operation of the other armature 2H, which cooperates with jetscorresponding to those shown at 4| and 42 in Figs. 1-3, and serves tocontrol the operation of the closure member from lowto high-fireposition when contacts 5| and 62 additionally engage. By thisarrangement, the system is always ready for operation with minimum con-'sumption of fuel for current generating purposes. If the pilot burnerflame is accidently extinguished, armature 86 is released and the mainvalve closes and cannot be reopened until the pilot burner is relighted,thus rendering the system safe.

Another advantage of the arrangement shown in Fig. 4 resides in the factthat, when both of the pairs of thermostat contacts are engaged and thusboth of the pilot valve operators energized,

,the thermostat is connected across points of equipotential in thecircuit and therefore no cur.- rent flows throughthe bimetallic memberand wire 11; it being assumed that the thermopiles are connected inseries, as shown, and that their generated E. M. F.s are equal, and alsothat the resistances of the coils, and of the branch circuits, areequal. The circuit then corresponds to a form of balanced Wheatstonebridge circuit, with the thermostat connected in the position usuallytaken by a null indicator. If a common source of current is employed, asin the circuit shown in Figs. 1-3, when both of the electromagnets areenergized current passes through the bimetallic member in an amountequal to the sum of the currents through the two coils; whereas by thearrangement shown in Fig. 4, current flows only in the outer circuit andnone (or a small amount, depending on the degree of balance of thebridge arms) passes through the bimetallic member.

The system of Fig. 4 is obviously adapted for the control of high-lowvalves other than of the type disclosed in Figs. 1-3; or of valves ofthe "modulating type, wherein additiona1 electrical energy is requiredfor full opening of the valve. Further, if the electric valve-operatoris sufllciently sensitive, it can be employed for direct control of fue1to the burner, i. e., without the requirement for auxiliarypressure-operated means. I wish it to be understood that still furthermodifications may be made without departing from the spirit of theinvention, and that I intend therefore to be limited only by the scopeof the appended claims.

I claim as my invention:

In a system for controlling the operation of a fluid-fuel consumingheating apparatus: a main burner; a supplemental burner; electricallycntrolled valve means for supplying fuel to said main burner in amountssufficient to produce a low-fire or a high-fire condition thereat, saidvalve means requiring a predetermined amount of electrical energy inorder to produce said lowflre condition and a greater amount in order toproduce said high-fire condition; a first thermoelectric generatingdevice of limited capacity, heated by the flame of said supplementalburner, for supplying only said predetermined amount of energy to thevalve means; and a second thermoelectric generating device, heated bythe flame of said main burner, for supplying to said valve means energyin an amount sufiicient for the establishment of said high-firecondition; the flame of said supplemental burner being so small that itis incapable of effectively heating both of said thermoelectricgenerating devices.

2. In a system for controlling the operation of a fluid-fuel consumingheating apparatus: a main burner, a supplemental burner, firstelectrically controlled valve means for supplying fuel to said mainburner in an amount sufiicient to produce a low-flrecondition thereat, afirst thermoelectric generating device heated by the flame of saidsupplemental burner for energizing said first valve means, secondelectrically controlled valve means for supplying fuel to said mainburner in such amount that a high-fire condition is estabbllshedthereat, and a second thermoelectric generating device heated by theflame of said main burner for energizing said second valve means, theamount of energy produced by said first thermoelectric generating devicebeing insufficient for both of said valve means and the flame of saidsupplemental burner being so small that it is incapable of efiectivelyheating both of said thermoelectric generating devices.

3. In a system for controlling the operation of a fluid-fuel consumingheating apparatus: a main burner; a continuously-burning pilot burnerfor said main burner; electrically controlled valve means for supplyingfuel to said main burner in amounts sufiicient to produce a low-fire ora high-fire condition thereat, said valve means requiring apredetermined amount of electrical energy in order to produce saidlowfire, condition and a greater amount in order to produce saidhigh-fire condition; a first thermoelectric generating device of limitedcapacity, heated by the flame of said pilot burner, for supplying onlysaid predetermined amount of energy to the valve means; a secondthermoelectric generating device, heated by the flame of said mainburner, for supplying to said valve means energy in an amount sufiicientfor the establishment of said high-fire condition; the flame of saidpilot burner being so small that it is incapable of effectively heatingboth of said thermoelectric generating devices; and means, movable inresponse to change in a condition resulting from the operation of saidmain burner, for controlling the energization of, said valve means bysaid thermoelectric generating devices.

4. A control system, as defined in claim 3, wherein said conditionresponsive means is effective, in the movement thereof in one direction,to first effect energzation of said valve means by said firstthermoelectric generating device, and, by continued movement in the samedirection, to effect energization of the valve means by said secondthermoelectric generating device.

5. In a system for controlling the operation of a fluid-fuel consumingheating apparatus: a main burner; a continuously-burning pilot burnerfor said main burner; first electrically controlled valve means forsupplying fuel to said main burner in an amount suflicient to produce alowfire condition thereat; a first thermoelectric generating device,heated by the flame of said pilot burner, for energizing said firstvalve means; second electrically controlled valve means for supplyingfuel to said main burner in such amount that a high-fire condition isestablished thereat; a second thermoelectric generating device, heatedby the flame of said main burner, for energizing said second valvemeans; the amount of energy produced by said first thermoelectricgenerating device being insuflicient for both of said valve means, andthe flame of said pilot burner being so small that it is incapable ofeffectively heating both. of said thermoelectric generating devices; andmeans, movable in response to change in a condition resulting from theoperation of said main burner, for controlling the energization of saidvalve means by said thermoelectric generating devices, and acting in itsmovement in one direction to first effect energization of said firstvalve means by said first thermoelectric generating device, and, bycontinued movement in the same direction to effect energization of saidsec ond valve means by said second thermoelectric generating device.

WILLIAM A. RAY.

